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Geodetic tools and data

The Canadian Geodetic Survey (CGS) has publicly available tools and desktop applications to help surveyors, engineers, glaciologists and other professionals calculate accurate positions on the Canadian landmass. Learn more about each tool below to understand which one suits your needs.

Access the tools

Access the tools
Canadian Spatial Reference System Precise Point Positioning (CSRS-PPP) CSRS-PPP is an online application for global navigation satellite systems (GNSS) data post-processing. It uses precise satellite orbit, clock and bias corrections derived from a global network of receivers to determine accurate user positions anywhere on the globe, regardless of proximity to reference stations. Submit Receiver INdependent Exchange (RINEX) format observation data from single or dual-frequency receivers operating in static or kinematic mode over the Internet, and recover enhanced positioning precisions in the North American Datum of 1983 of the Canadian Spatial Reference System (NAD83(CSRS)) or the International Terrestrial Reference Frame (ITRF).
Canadian Active Control System (CACS) CACS consists of continuously tracking GNSS stations, referred to as active control points (ACPs). They’re equipped with a high-precision, dual frequency GNSS receiver, and some also include an atomic frequency standard. Download station coordinates, metadata and GNSS observation data from the national network (CACS), as well as the regional, provincial and municipal networks whose data are distributed by CGS.
Real-Time Kinematic (RTK) networks RTK networks include publicly and commercially operated RTK networks in Canada with continuously tracking GNSS receivers. They’re used for either real-time network or single-base RTK positioning solutions. You can download official station coordinates and view position time series for RTK networks that operate in Canada and have entered into either an RTK compliance or a data-sharing agreement with CGS.
Passive control networks The interface of the passive control networks provides access to station descriptions and coordinates from the Canadian Base Network, the High Precision 3D Geodetic Network, and the vertical and horizontal control networks.
Vertical Datum Transformations Access height differences at benchmarks between various vertical datums including CGVD28, CGVD2013, IGLD85, local chart datum, and local Mean Water level.
Canadian Gravity Standardization Network (CGSN) Use the CGSN to access gravity standard and metadata for both the absolute and relative networks. The CGSN has some 1,600 control stations distributed throughout Canada, but it is being replaced by a limited number of stations measured accurately by absolute gravimetry. The adjustment of the CGSN (relative stations) is based on the International Gravity Standardization Network (IGSN71), so the datum definition is considered accurate to several tens of microgals.
TRX TRX is a coordinate transformation tool that allows you to transform between NAD83(CSRS) and ITRF realizations; convert coordinates between geographic, Cartesian and mapping projections (UTM, MTM, and stereographic); and transform coordinates between epochs using the predicted velocities from the Canadian Velocity Grid.
National Transformation Version 2 (NTv2) The NTv2 tool provides a national standard for transforming coordinates (geographic, UTM/MTM/stereographic) between the North American Datum of 1927 (NAD27), the Average Terrestrial System of 1977 (ATS77), the North American Datum of 1983 (NAD83(Original)) and NAD83(CSRS) reference systems using binary grid shift files (.GSB format) where available. The transformation is 2D (horizontal), so heights are not required.
Coordinate transformations Sign in to access the 3D, horizontal and vertical coordinate transformation parameters, as well as the NAD83(CSRS) velocity grid to propagate coordinates between epochs.
GPS·H Use GPS·H to convert your GNSS ellipsoidal heights (h) that are in either NAD83(CSRS) or ITRF, to orthometric heights (H, heights above mean sea level) by applying a gravimetric or hybrid geoid model. You can also use it to calculate the reversed conversion (H to h) and the conversion between two vertical datums. It provides a user-friendly interface to perform height conversions, which can be expressed as either:
  • Orthometric Height (H) = Ellipsoidal Height (h) - Geoid Height (N)
  • Orthometric Height (Datum b) = Orthometric Height (Datum a) + delta H (dH)
Geoid models Sign in to access the geoid models and height system conversions that are available, as well as their metadata.
Desktop applications Several Windows desktop applications are also available for download. These include GPS·H, TRX, NTv2 and PPP_direct, which provides a convenient way for submitting data to our CSRS-PPP service.
INDIR The INDIR Direct-Inverse computation tool performs either a geodetic direct or inverse computation. Direct computation uses a starting point’s geographic coordinates — an azimuth and a distance — to compute the geographic coordinates of the end point. Inverse computation uses the geographic coordinates of two points to compute azimuth and distance.
GNSS calendar Use the GNSS calendar to view on a Gregorian calendar the day of year, the Modified Julian Day, the GNSS week number and the GNSS days of the week.

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